Apparatus for processing textile yarns



Aug. 20 1957' N. J. STODDARD ETAL 7 2,803,105

APPARATUS FOR PROCESSING TEXTILE YARNS Filed Jan. 4, 1954. s Sheets-Sheet 1 v- J s 4 22 |wmmmlnmmmml INVENTORS."

ATTORNEYS.

- Aug. 20; 1957 N. J. STODDARD ETAL APPARATUS FOR PROCESSING TEXTILE YARNS Filed Jan. 4, -195 4 s Sheets-Sheet 2 INVENTORS. Mt/mplfas :ZSZua'da rd A2 a l7 I72 M4 5&2

- ATTORNEYS 14L? iL Aug. 20, 1957 N. J. STODDARD ETAL- 2,803,105

APPARATUS FOR PROCESSING TEXTILE YARNS.

Filed Jan. 4, 1954 5 Sheets-Sheet 5 TIC-Z61 War; 9 M bl ATTORNEYS.

Aug. 20, 1957 NJ. STODDARD ET AL 2,803,105

APPARATUS FOR PROCESSING TEXTILE YARNS Filed Jan. 4; 1954 s Shegts-Sheet 4 INVENTORS! jVz'cfioiaselSiaddard d2.

: W A .90 9 ,9; I j ma i l A TTORNEYS N. J. STODDARD ET AL APPARATUS FOR PROCESSING TEXTILE YARNS Aug. 20, 1957 5 Sheets-Sheet 5 Filed Jan.

INVENTORS.

ATTORNEYS.

United States Patent APPARATUS FOR PROCESSING TEXTILE YARNS Nicholas J. Stoddard, Berwyn, and Warren A. Seem, Chester Springs, Pa., assignors, by mesne assignments, to Universal Winding Company, Cransten, R. L, a corporation of Massachusetts Application January 4, 1954, Serial No. 401,952

7 Claims. (Cl. 57-34) This invention relates to apparatus for processing thermoplastic textile yarns. More particularly it is concerned with apparatus useful in processing polyamide and other thermoplastic yarns such as nylon, Vinyon, Orlon, Velon,

Dacron, saran and the like (as distinguished from yarns stepwise methods which had to be resorted to hereto-- fore, for the production of improved monofilament, multi-filament, or spun thermoplastic yarns which are of improved uniformity throughout as regards their physical characteristics, i. e., denier size, elongation, elasticity, strength, yield value, contractile force, shrinkage, residual shrinkage, torsion and the like; permanently stabilized uniformly crimped, wavy or fluffed thermoplastic yarns; straight thermoplastic yarns of the kinds disclosed in U. S. Patents Nos. 2,353,666 and 2,411,132; aswell as improved uniformly stabilized ply yarns whereof the com-- ponents may all be thermoplastic, or some of them may be of rayon or the like, or of silk, cotton, linen, or other non-thermoplastic materials.

Other objects and attendant advantages will appear from the following description of the attached drawings, wherein:

Fig. l is a fragmentary view, in front elevation, of a thermoplastic yarn processing apparatus conveniently embodying our invention in one form.

Fig. 2 is a fragmentary detail section on a larger scale taken as indicated by the angled arrows II-II in Fig. 1, showing in detail a specially constructed heating device and an associated specially constructed tensioning means incorporated in the apparatus.

Fig. 3 shows the heating device in top plan.

Figs. 4 and 5 are views corresponding respectively to Figs. 2 and 3 of a modified form of heating device.

Fig. 6 is a detail sectional view taken as indicated by the angled arrows VIVI in Fig. 2.

Fig. 7 is a view like Fig. 6 showing an alternative type of tensioning means.

Fig. 8 is a fragmentary view, in front elevation, like Fig. 1 of a thermoplastic yarn processing apparatus embodying our invention in another form.

Fig. 9 is a fragmentary view showing the apparatus of Fig. 8 in transverse section.

Figs. 10, 11 and 12, respectively, show the front view,

2,893,105 Patented Aug. 20, 1957 cially constructed high speed spindle provided in the apparatus of Figs. 8 and 9, the section being taken as indicated by the angled arrows XIIIXIII in Fig. 8.

With more specific reference first to Fig. 1 of the drawings, the apparatus there illustrated is basically what is known in the textile art as an up-twister. One of the usual spindles for a package P of yarn Y to be processed is indicated at 2, one of the traverse guides at 3, the traverse rail at 4, the take-up spool for the processed yarn at S, the drive roll for the spool at 6, and the shaft for the drive roll at 7, said spindle having a diametrically enlarged portion at the bottom tangentially contacted by the belt 8.

In adapting such an up-twister to the purposes of our invention, we arrange in the interval between the spindle 2 and the traverse guide 3, a specially designed heating device 10, and immediately below said device, a specially constructed tensioning means 11 along the line of up ward travel of the yarn Y from the supply package P to the take-up spool S.

As presently explained, the device 10 is electrically heated, current being conducted to it through two fixed horizontal bus bars 12 and 13' whereto said device is secured, with interposition of insulation bushings 14, by screws 15 and 16. as best shown in Fig. 2. The required degree of heat is uniformly maintained by current at a constant voltage -(not exceeding twenty-four volts for personal safety) through an automatic induction voltage regulator 17 from-a power line 18, 19, said regulator being connected by conductors 20, 21 to a manually adjustable induction voltage regulator 22 connected in turn by conductors 23, 24, to the primary of a step-down transformer 25 in circuit through conductors 26, 27 with the bus bars 12, 13. The output of the induction voltage regulator 17 is automatically governed by a thermally-responsive sensing means 28 incorporated in the heating device 10. The

Y automatic and the manual induction voltage regulators 17 and 22 and the thermostatic sensing means 28 may all be of any approved standard and commercially available types by cooperation of which the temperature in the heating device is modulated compensatively with changes in ambient or room temperature and transfer of heat to a yarn travelling therethrough. Also included in the lines 18, 19 and 20, 21 respectively are suitable manually operable safety hand switches 29 and 30.

The heating device As best seen in Figs. 2 and 3, the heating device 10 comprises a tube 32 of non-ferrous material and of small diameter and bore, through which the yarn Y is passed, said tube being exteriorly insulated as at 33 with glass or other electricalv insulation, and surrounded by a coil 34 of'resistance wire. As further shown, the tube 32 is embedded in a thick walled jacket 35 of electric and thermal insulation which may be of fiber glass or of Sil-O- Cel granules encased in a thin cylindrical metallic shell 36. At the top and at the bottom, the shell 36 is partly closed by covers 37, which also may be of sheet metal, with interposition between them and. the jacket material of disks 38 of Transite or the like to minimize heat transfer from the hot tube 32 to said shell. Fitted over the op- 1 posite ends of the tube 32 and passing through the disks a side view and the top plan view of a specially con- 38, are hard wear-resistant bushings 39 of porcelain or the like which prevent cutting of the tube by the yarn passing through it. It is to be particularly noted that the winding pitch of the heating coil increases progressively from the bottom of the tube 32 at which the yarnenters to the mid height of the tube and progressively decreases at a similar rate toward the top or exit endof said tube. As a result, a greater amount of electrical energy is provided at the entrant and exit ends of the tube thereby making possible the maintenance of a desired uniform temperature throughout tube 32 and the use of a much shorter tube than otherwise would be required. The lead 40 from one end of coil 34 is extended to the exterior through the insulation jacket 35 to the screw 15, and the lead 41 from the other end of said coil to the screw 16, with interposition in the latter lead of a hand switch which is diagrammatically indicated at 42 in Figs. 1 and 2 and shown as insulatedly mounted on bus bar 12.

The tensioning means The tensioning or restraining means 11 comprises, in this instance, a small V-grooved wheel 45 (Figs. 2 and 6) about which the yarn Y is passed one or more times, said wheel being freely revolvable about the laterally bent endof a supporting shank member 46, and is engaged by a friction disk 47 which is pressed by a spring 48, the pressure of the latter being finely regulatable by means of a thumb nut 49 threadedly engaged upon the distal end of said shank member. By this means it is possible to regulate the tension of the yarn in correlation to the prescribed temperature to which the yarn is heated and to the linear speed of travel of the yarn to maintain the latter at a selected uniform tension relative to the contractile force and thermal characteristics of the yarn. As best shown in Fig. 2, the shank member 46 extends through a vertical slot 50 in a bracket bar 51 suspended from bus bar yarn, said guide being fixed in adjusted position by clamp nuts 54.

Modified heating device In the modified heating device 10a of Figs. 4 and 5 which may be used in lieu of the one illustrated in Figs. 2 and 3, the yarn tube 32a is axially arranged in an evacuated round ended shell 36a of non-collapsible material, with its ends sealed in bushings 39a hermetically set into the ends of said shell. By this means it is possible to regulate the tension of the yarn in correlation to the prescribed temperature to which the yarn is heated and to the linear speed of travel of the yarn to maintain the latter at a selected uniform tension relative to the contractual force and thermal characteristics of the yarn. In this instance, the heating coil 34a is non-inductively wound about the tube 32a which has an exterior coating of insulation like that of the'tube 32 of the first described heating unit. In all other respects, the modified heating device a may be considered to be generally like the device 10 and to function in an analogous capacity.

Modified yarn tensioning means In the modified yarn tensioning or restraining means 11a of Fig. 7, a pair of opposing friction disks'45a are shown instead of a roller, these being freely revolvable about the laterally turned end of the supporting shank 46a and maintained in pressure engagement with the yarn Y as it passes between them, by a spring 48a which is finely regulatable by the thumb nut at 4%. With the modified tensioning means 11a substituted for the means 11 in the apparatus of Fig. 1, a somewhat different effect is produced on the yarn as will be explained later.

Operation Again referring to Fig. 1, the yarn from the supply package P is threaded upwardly through one eye of the flyer 55 associated with spindle 2, then through the guide 53, then wrapped about the small wheel 45 of the tensioning means 11 in the manner previously stated, then through the tube 32 of the heating device 10, and finally over the traverse guide 3 enroute to the take-up spool S. For the processing of twisted nylon yarn, for example, the induction voltage regulator is adjusted for maintenance of an effective temperature of 250 P. which is modulated with changes in ambient or room temperature and rate of heat transfer to the yarn by the thermostatic means 28 for maintenance of heat substantially constant in the device 10. In being ravelled from the supply package P in Fig. 1, the yarn is twisted by rotation of the package before it passes to the tensioning means 11 and enters the tube of the heating device 10 enroute to the take-up spool S. By reason of adequate frictional engagement of the yarn with the small wheel 45 when wrapped about it or alternately the adequate frictional engagement of the yarn with the tines of the comb-like vanes 55 and 56 of an alternate tension device shown in Figs. 10, 11 and 12, the twist is inserted in the yarn prior to its entry into the heating device, the twist being subsequently set by heating and cooling of the yarn in the interval of its travel between the tensioning device and the take-up spool S. When an alternative tension device like that shown in Fig. 7 is utilized, the tangential frictional contact of the disks 45a upon the yarn is such that the disks permit the yarn passing therethrough to turn upon its axis and be twisted in the heated zone where it has been made more ductile, with stabilization of the yarn taking place as it cools in its travel between the heated zone and the take-up spool S. By adjusting the tensioning devices so that the restraint imposed is equal to the contractile force of the yarn, no stretching or shrinking of the yarn will take place. On the other hand, if the adjustment of the tensioning means is made less than the contractile force of the heated yarn, shrinking of the yarn will take place during the heating, while if the adjustment is made greater than the contractile force, the yarn will be stretched during the heating.

Many of the irregularities in the physical characteristics of commercially delivered thermoplastic yarns are substantially corrected by our means of applying uniform heat to the yarn while under uniform tension as for example, sectional lengths of yarn, stretched less than other sections in the manufacturers producing thereof will stretch more under a given tension and temperature, and uniform elevated temperatures while under various uniform tensions, will improve properties of the yarn such as dyeing, tensile strength, modulus of elasticity and the like. Also our means of quickly heating and cooling the yarn prevents heat degradation normally resulting from prolonged heating of thermoplastic yarns.

Fig. 1 illustrates the manner of equipping a conventional Lip-twister with the herein referred to heating and tensioning devices, but in the practice of our invention we similarly equip all throwing or yarn processing machines such as winding, twisting, twisting-untwisting, plying, coning, copping, nubbing, drying, dyeing, coating, singeing and sizing machines and the like.

Alternative form of apparatus Like the apparatus of Fig. 1, the alternative apparatus of Figs. 8 and 9 is basically an up-twister converted to the purposes of our invention, the usual parts of'the machine being designated by the same reference numerals previously employed, with addition however in each instance of the letter at for convenience of more ready distinction. In this case in adapting the tip-twister to the purposes of our invention, we have provided it with a special overhead creel 9 for the yarn package P which is to be processed, a specially constructed tensioning device 11x different from either of the two hereinbefore described, and a specially constructed spindle 2x, the heating device 10x here shown being like the one illustrated in Fig. 2.

T ensioning device By reference more particularly to Figs. 10, 11 and 12, it will be noted that the tensioning device 11x comprises two comb-like vanes 55 and 56 between the alternating tines of which the yarn Y is passed. Vane 55 is fixedly supported between a pair of vertically-spaced forwardlyprojecting lugs 57 Ora bracket plate 58, while vane sets swingable about a hinge pin 59 between another pair of vertically-spaced forwarding-projecting lugs 60 of said plate. The swingable vane 56 is connected by a tension spring 61 to a vertical lever 62 fulcrumed at 63 on a rearward projection 64 at the top of the plate 58. Y The lower or distal end of lever 62 bears against a screw 65 threadedly engaged in plate 58. By means of screw 65, it is possible to vary the force of the spring 61 and, in turn, the pressure exerted by the wing 56 upon the yarn Y to regulate the drag or tension imparted thereto. Thus the tension of the yarn may be correlated to the prescribed temperature to which the yarn is heated and the linear speed of travel of the yarn as previously described. The jam nut at 66 serves as a means for securing the screw 65 against accidental displacement in adjusted position.

Special spindle Our improved twisting and untwisting spindle illustrated in detail in Fig. 13 is an improvement over the types of spindles disclosed in U. S. Patents Nos. 2,089,198 and 2,089,199.

- As shown, the spindle 75 is relatively short in length and formed by two sections of light weight tubing preferably of steel, the lower section being telescopically forcefitted partway into the upper section and having a small bore of a diameter to freely pass the travelling yarn. In actual practice, the upper section of the spindle 75 may be 2 in. long and have a diameter of /2 in., and the lower section may be 3 /8 in. long with an outside diameter of A in. and a bore of 7 in., the whole weighing approximately 2% ounces and the total length of the tube being approximately 4% inches. The periphery of the upper section serves as a driving surface in contact with the belt 8x of the otherwise conventional spinning machine. Thus the tension of the yarn may be correlated to the prescribed temperature to which the yarn is heated and the linear speed of travel of theyarn as previously described. The spindle 75 is journalled in a pair of high speed anti-friction bearings 76, 77 which are vertically spaced by a sleeve 83 approximately 1 in. long surrounding the lower section of the spindle. The bearings 76, 77 are lodged, with interposition of rubber cushioning annuli 84, 84 embracing outer races 96, 97, within a compact cylindrical housing 78 which extends downward, with circumferential clearance, through an opening 100 in the swing arm 79, and which itself is cushioned by a rubber washer 101 interposed between a flange 102. adjacent the top thereof and the top surface of said arm, and a similar washer 103 interposed between the bottom surface of said arm and a clamp nut 104 threadedly engaged on the lower protruding portion of said casing. As shown, the casing 73 is open at the top but protected against ingress of dirt or lint by a disk 105, with a pendent circumferential overhanging flange, rotative with the spindle and secured between the lower end of the upper section of said spindle and the top of the inner race 98 of the upper ball bearing. It is to be noted that the rubber cushioning annuli 84 for the ball bearings 76, 77 respectively are seated upon circumferential shoulders 106, 107 circumferentially of the casing 78, and that the lowerbearing 77 is held against upward displacement by inward radial projections of a semicircular spring keeper 108 element, and that a clamp nut 109 threadedly engaged upon the lower section of the spindle and contacting the bottom of the inner race 99 of the lower ball bearing 77 serves to hold the spindle in the assembly, the lower end of the latter being somewhat reduced in diameter and extending through an axial clearance aperture 110 in the bottom of the casing. A small flanged roll 82 within the top end of the upper section of the spindle is freely revolvable about a crosswise axis pin 111. It is also to be particularly observed that the opposing side portions of the top' end of the upper section of the spindle are cut away concavely as at 112 on a radius greater than that of the flanges of the roll 82.

Of importance in the carrying on of all of the objects of this invention are the improvements in and the advantages of our twisting-untwisting spindle assembly over previously disclosed twisting-untwisting spindles, these advantages being: the interchangeability of the spindle with conventional spindles on conventional twisters; the one-half inch outside diameter of the driving surface of the spindle 75 results, without changing the belt speed, in about double the spindle speed of conventional spindles which usually have approximately one inch outside diameter of their driving surface; the thin wall, short 2 inch length and small one-half inch outside diameter result in a spindle with a substantially irreducible minimum of weight and inertia; the small one-half inch outside diameter and the short 2 inch length of the exposed upper section of the revolving spindle result in a substantially irreducible minimum of windage; the wall thicknessof the hollow spindle and the 2 inch length of the exposed section of the revolving spindle are subtsantially irreducible minima for such type of spindle to be driven in excess of 20,000 R. P .M. by a conventional flat bolt; the joining of two metal tube sections provides the most economical means of pro reduce friction losses to substantially an irreducible minimum when operating in excess of 20,000 R. P. M. under the known inertia, friction, windage, vibratory and work loads, and requiring no added lubrication for years; the 1 inch spacing between the ball bearings 76, 77 is substantially the optimum for operation in excess of 20,000 R. P. M. under the known operating loads; the rubber housing annuli 84 and rubber washers 101 and 103 absorb vibratory shocks and reduce vibratory loads, friction losses, Windage and wear; the concaved roundings 112 at the upper end of the hollow spindle permit easy threading of the reverse twist roll 82; the cover disk 105 protects the ball bearings from dust, lint and yarn waste; the retaining spring 108 serves as a most economical yet reliable means of holding the hollow spindle and bearings in position in the bearing housing 78 as well as an easy means to release the same when required; and the reverse twist roll has many advantages herein more fully set forth.

We have found that, due to the low inertia, friction, windage, vibratory and work loads of our improved spindle, it is possible to operate the spindle at more than twice the speed of conventional spindles, twisting a like yarn the same degree, without any increase in energy consumption; and we have also found that this saving in energy is adequate to operate our heating devices according to the teachings of this invention. Moreover, the design of our improved machine is such as to permit the use of large delivery packages, the absence of any revolving yarn packages makes for less yarn breakage, the twisting and untwisting at one time and at high speeds and the doubling prior to and/or after twisting and untwisting reduces the machine operators work load, all of which results in substantial labor saving.

Reverse twist roll 82 of Fig. 13 is of particular importance in carrying out the objects of this invention; and it is of importance that anti-friction oilless bearings are utilized, that the approximate dimensions of the roll are A Width, /2" diameter 30 degree tapered flanges, diameter roll face A; in width, and that the face that substantially no added tension is applied to the yarnat this critical point of its travel; the outside dimensions are important to create adequate windage to cool the yarn with a minimum of power consumption; the taper and depth of the flanges are essential to control the shape of yarn balloon and flow of air to cool the previously heated travelling yarn; the diameter of the roll face is of importance to provide adequate traction to minimize the number of wraps of the yarn about the roll necessary to insure the insertion of one full turn of twist for each revolution of the spindle and to create an adequate balloon to insure adequate cooling of the yarn before the untwisting; the width of the face of the roll is of importance to insure no overlapping of the wraps of yarn about the roll but aded traction as a result of the centrifugally induced abutting relation of one wrap of travelling yarn against the next; the smooth polished surfaces of the roll face and tapered flanges are, important to prevent catching or chaffing of the yarn; and the size and shape of the tapered flanges in relation to the face of the roll are of importance for ease of removal of yarn waste.

In practice we have found it to be very desirable and economical to place more than one delivery package upon the supply creel for each spindle and then travel two or more ends of similar or dissimilar yarn through the same tension device, the thermal unit and the twisting-anduntwisting spindle, but in all instances at least one of the ends of yarn is thermoplastic.

We have also found it to be very practical and economical to travel similar or dissimilar yarns from two or more spindles on one take-up package, with the ends so doubled and all having been twisted in one direction or in any combination of different directions; the aforesaid doubling being facilitated in some instances by utilizing overhead thread guides between adjacent machines so as to wind onto the take-up package of one machine, yarn that has been twisted etc. on the adjacent machine.

Operation of modified apparatus For the purposes of illustration let it be assumed that the yarn Y is in the form of a continuous multi-filament of nylon or the like. As it passes down through the device it is uniformly heated to a temperature within twenty degrees of the melting point of the thermoplastic, the temperature being predetermined by adjustment of the manual induction voltage regulator 22x in accordance with the rate of linear speed at which it is travelled, the temperature being automatically modulated as in the first described embodiment compensatively with changes in ambient or room temperature and transfer of heat to the travelling yarn by action of the sensing means 28, and the means 11 being adjusted for maintenance of the desired tension less than the yield value of the yarn during the heating thereof. While in 'a plastic state, the yarn is twisted as it traverses the device 10 by the action of the spindle 2x and cooled by ballooning and radiation in the interval between the outlet end of the heated tube 32 of said device and small roll 82, the yarn being wrapped one or more times about the small roll 82 of the twistinguntwisting spindle as previously explained; and the cooling being enhanced by contact of the yarn with the face and smooth sloping sides of said roll. The yarn is thus adequately cooled before it becomes untwisted which occurs as it leaves frictional contact with roll 82 and thereafter passes through and out of the lower end of the spindle tube 75 enroute, beneath the two fixedly positioned guide wheels 89 and 90 over the guide rod 9?. and the reciproeating traverse guide 3, to the driven take-up spool S. As a result of this continuous processing in accordance with our invention, a substantially permanent crimp, wave or fluff is set into the yarn. Care must, of course, be exercised to maintain the proper correlation between heat, speed and tension, for'if the yield value of the heated yarn being processed is intermittent or uniformly exceeded by tensile stress, the resultant yarn, after untwisting, will be uneven and lack uniform crimp, wave or fluff and the degree of the crimp, wave or fluff will be relative to the degree to which the tension is exceeded in yield value. The degree and permanency of the crimp wave or flulf is attained by maintaining the treating temperature well up to the melting point of the thermoplastic, i. e., not less than forty percent below the melting point. By maintaining a low tension, the yarn will be permitted to shrink in the processing, while by subjecting it to a relatively high tension, a corresponding amount of stretching or elongation will take place during the heating. It is to be noted that in the apparatus of Figs. 8 and 9, the yarn is restricted against turning about its axis by frictional engagement with tension device 11x, while revolving spindle 2x, with the yarn in frictional engagement with roll 82 attached thereto, turns the yarn upon its axis, and since the portion of the yarn which is at the moment heated to a more ductile state by device 10 offers the least resistance to being twisted, much of the insertion of twist takes place in the heated portion of the yarn.

A spun yarn originally formed from thermoplastic staple or fibers when processed according to our invention will of course be attended by results similar to those described above in connection with continuous multi-filament thermoplastic yarn.

If desired, the yarn may be dyed or sized as an incident to the processing, and in accordance with our invention, we have provided a dye or sizing applicator in Fig. 9 through which the yarn is passed enroute to the heating device It), the diverted path of the yarn being indicated at Y in dotted lines. In passage of the yarn through the restricted heated zone at elevated temperature in the device 10, the dye is effectively developed and set, or the sizing is dried as will be readily understood.

With the apparatus of Figs. 8 and 9, it is also possible to produce straight compact twisted thermoplastic yarns of the kinds disclosed in the two patents hereinbefore referred to, whose active and latent torsional forces are eliminated or controlled by twisting the ends from 3% to 60% beyond the twist desired in the final yarn, setting the twist, and then twisting the yarn in the opposite direction a number of turns. In this case the yarn is previously twisted to the ultimate twist desired on conventional twisters, and said twisted yarn is mounted upon supply creel 9 and additionally twisted under heat and correlated tension, cooled and reverse twisted the identical number of turns as twisted by the use of the apparatus of Figs. 8 and 9.

With the apparatus of Figs. 8 and 9 it is also possible to process plied yarns by placing two or more packages of yarn to be processed on the supply creel, as for example, a second strand Y2 is supplied from a second package P supported on creel 9 above supply package P for the first end.

It is of course to be understood that in the two types of illustrated apparatus, a heating device 10 or 10x and a tensioning device 11 or 11x are provided for each spindle 2 or 2x, and that in either instance, heating devices of the construction shown in Figs. 4 and 5 may be substituted, if desired or deemed more convenient, for the heating devices 10 or Mix, with attainment of the same desired uniform effects in the processed yarns. It is to be further understood that we do not consider ourselves limited to the precise details of construction herein shown by way of example, since these are obviously subject to variation within the scope of the broader claims hereto appended.

Having thus described our invention, we claim:

1. Apparatus for thermally processing thermoplastic yarn comprising a support for a supply of yarn, wind-up means for the processed yarn spaced from said support and operable to draw the yarn continuously at a selected linear speed from the supply to said wind-up means, an electrically energized heating device defining a restricted thermally isolatedheated zone for passage of the yarn 9 l therethrough to heat the yarn to a prescribed temperature, means operable to twist the yarn before passage thereof through said heated zone, control means operable automatically to regulate the supply of heat energy tosaid zone compensatively according to the rate of transfer of heat to the yarn to maintain said zone uniformly at the temperature required to heat the yarn to said prescribed temperature, tension means operable to maintain the yarn ate uniform tension during passage thereof through said heating device and to the wind-up means, and means to regulate the tension means to control-the tension of the yarn in correlation to the prescribed temperature and linear speed of travel of theyarn to maintain the latter at a selected uniform tension relative to' the contractile force and thermal characteristics of the yarn;

2. Apparatus for thermally processing thermoplastic yarn comprising a support for a supply of yarn, wind-up means for the processed yarn spaced from said support and operable to draw the yarn continuously at a selected linear speed from the supply to said wind-up means, means to apply a liquid to the yarn passing from said supply, an electrically energized heating device defining a restricted thermally isolated heated zone for passage of the yarn therethrough to heat the yarn to a prescribed temperature, means operable to twist the yarn before passage thereof through said heated zone, control means operable automatically to regulate the supply of heat energy to said zone compensatively according to the ambient temperature and rate of transfer of heat to the yarn to maintain said zone uniformly at the temperature required to heat the yarn to said prescribed temperature, tension means operable to maintain the yarn at a uniform tension during passage thereof through said heating device and to the wind-up means, and meansto regulate the tension means to control the tension of the yarn in correlation to the prescribed temperature and linear speed of travel of the yarn to maintain the latter at a selected uniform tension relative to the contractile force and thermal characteristics of the yarn.

3. Apparatus for thermally processing thermoplastic yarn comprising a support for a supply of yarn, wind-up means for the processed yarn spaced from said support and operable to draw the yarn continuously at a selected linear speed from the supply to said wind-up means, an electrically energized heating device defining a restricted thermally isolated heated zone for passage of the yarn therethrough to heat the yarn to a prescribed temperature, a false-twist device operable to twist the yarn before passage thereof through said heated zone and to untwist the yarn after said passage through the heated zone, control means operable automatically to regulate the supply of heat energy to said zone compensatively according to the rate of transfer of heat to the yarn to maintain said zone uniformly at the temperature required to heat the yarn to said prescribed temperature, tension means operable to maintain the yarn at a uniform tension during passage thereof through said heating device and to the windup means, and means to regulate the tension means to control the tension of the yarn in correlation to the prescribed temperature and linear speed of travel of the yarn to maintain the latter at a selected uniform tension relative to the contractile force and thermal characteristics of the yarn.

4. Apparatus for thermally processing thermoplastic yarn comprising a support for a supply of yarn, wind-up means for the processed yarn spaced from said support and operable to draw the yarn continuously at a selected linear speed from the supply on the support to said windup means, means to apply a liquid to the yarn passing from said supply, an electrically energized heating device defining a restricted thermally isolated heated zone for passage of the yarn therethrough to heat the yarn to a prescribed temperature, a false-twist device operable to twist the yarn before passage thereof through said heated zeiie and to untwist the yarn after said passage through the heated zone, control m eans operable automatically to regulate the supply of heat energy to said zone compensatively according to the ambient temperature and rate of -transfer of heat to the yarn to maintain said zone uniscribed temperature and linear speed of travel of the' yarn to maintain the latter at a selected uniform tension relative to the contractile force and thermal characteristics of the yarn.

5. Apparatus for thermally processing thermoplastic yarn comprising a support for a supply of yarn, wind-up means for the processed yarn spaced from said support and operable to draw the yarn continuously at a selected linear speed from the supply to said wind-up means, means to apply a liquid dye to the yarn passing from said supply, an electrically energized heating device defining a restricted thermally isolated heated zone for passage of the yarn therethrough to heat the yarn to a prescribed temperature, a false-twist device operable to twist the yarn before passage thereof through said heated zone and to untwist the yarn after said passage through the heated zone, control means operable automatically to regulate the supply of heat energy to said zone compensatively ac cording to the ambient temperature and rate of transfer of heat to the yarn to maintain said zone uniformly at the temperature required to heat the yarn to said prescribed temperature, tension means operable to maintain the yarn at a uniform tension during passage thereof through said heating device and to the wind-up means, and means to regulate the tension means to control the tension of the yarn in correlation to the prescribed temperature and linear speed of travel of the yarn to maintain the latter at a selected uniform tension relative to the contractile force and thermal characteristics of the yarn.

6. Apparatus for thermally processing thermoplastic yarn comprising a frame structure, a support for a supply of yarn to be processed mounted at the upper part of said frame structure, wind-up means for the processed yarn mounted on said frame structure below the yarn support, tension means for the yarn supported from said frame structure and disposed at an elevation below the wind-up means, an electrically energized heating device mounted below said tension means and defining a restricted heated zone in alignment with the tension means for passage of the yarn to heat the same uniformly to a prescribed temperature, a spindle mounted on the frame below the heating device in alignment with the heated zone thereof operable to twist the strand of yarn before passage thereof through said heated zone and to untwist the yarn by passage through the spindle, guide means for supporting and directing the strand of yarn from said support in a downward direction to and through the tension means and thence downwardly through the heating device and spindle, guide means for supporting and directing the strand of yarn from said spindle and thence upwardly to said windup means, means to drive the spindle at a predetermined speed, and means to drive the wind-up means to draw a strand of yarn continuously at a selected linear speed from the yarn supply to said wind-up means, said tension means being operable to maintain the strand of yarn at a uniform tension during passage thereof downwardly through said heating device and upwardly to the wind-up means.

7. Apparatus for thermally processing thermoplastic yarn comprising a support for a supply of yarn, wind-up means for the processedyarn spaced from said support and operable to draw the yarn continuously at a selected linear speed from the supply to said wind-up means, an electrically energized heating device intermediate said support and wind-up means and defining a restricted thermally isolated heated zone for passage of the yarn therethrough to heat the yarn to a prescribed temperature,-

means operable to twist the yarn during passage thereof from said support to said wind-up means, control means operable automatically to regulate the supply .of heat energy to said zone to maintain said zone uniformly at the temperature required to heat the yarn to said prescribed temperature, tension means operable to maintain the yarn at a uniform tension during passage thereof through said heating device and to the wind-up means, and means to regulate the tension means to control the tension of the yarn in correlation to the prescribed temperature and linear speed of travel of the yarn to maintain the latter at a selected uniform tension relative to the contractile force and thermal characteristics of the yarn.

References Cited in the file of this patent UNITED STATES PATENTS Hynes May 27, Schweizer et a1 J an. 8, Hanfi Feb. 25, Dreyfus Mar. 15, Finlayson et a1 Mar. 15, Kunzle Mar. 8, Stockly July 12, Stockly Aug. 2, Burns Oct. 16, Eccles et al. Feb. 12, Hayes Oct. 21, Atkins Nov. 4, Heberlein et a1 Oct. 20, 

1. APPARATUS FOR THERMALLY PROCESSING THERMOPLASTIC YARN COMPRISING A SUPPORT FOR A SUPPLY OF YARN, WIND-UP MEANS FOR THE PROCESSED YARN SPACED FROM SAID SUPPORT AND OPERABLE TO DRAW THE YARN CONTINUOUSLY AT A SELECTED LINEAR SPEED FROM THE SUPPLY TO SAID WIND-UP MEANS, AN ELECTRICALLY ENERGIZED HEATING DEVICE DEFINING A RESTRICTED THERMALLY ISOLATED HEATED ZONE FOR PASSAGE OF THE YARN THERETHROUGH TO HEAT THE YARN TO A PRESCRIBED TEMPERATURE, MEANS OPERABLE TO TWIST THE YARN BEFORE PASSAGE THEREOF THROUGH SAID HEATED ZONE, CONTROL MEANS OPERABLE AUTOMATICALLY TO REGULATE THE SUPPLY OF HEAT ENERGY TO SAID ZONE COMPENSATIVELY ACCORDING TO THE RATE OF TRANSFER OF HEAT TO THE YARN TO MAINTAIN SAID ZONE UNIFORMLY AT THE TEMPERATURE REQUIRED TO HEAT THE YARN TO SAID PRESCRIBED TEMPERATURE , TENSION MEANS OPERABLE TO MAINTAIN THE YARN AT A UNIFORM TENSION DURING PASSAGE THEREOF THROUGH SAID HEATING DEVICE AD TO THE WIND-UP MEANS, AND MEANS TO REGULATE THE TENSION MEANS TO CONTROL THE TENSION OF THE YARN IN CORRELATION TO THE PRESCRIBED TEMPERATURE AND LINEAR SPEED OF TRAVEL OF THE YARN TO MAINTAIN THE LATTER AT A SELECTED UNIFORM TENSION RELATIVE TO THE CONTRACTILE FORCE AND THERMAL CHARACTERISTICS OF THE YARN. 